1. Field of the Invention
This invention is directed to a container with a tamper evident feature and a resealing closure and more particularly to a thermoplastic container with an integral seal in the outlet which, when twisted off by a cooperating means in a replaceable threaded cap, tears cleanly to leave a smooth opening in the container.
2. Prior Art
Recent event have heightened the interest in tamper-proof containers for a wide variety of products, most notably those consumed by or used on humans. While it is virtually impossible to thwart a most determined effort to tamper with a packaged product, the general objective is to make it as difficult as possible to do so without detection. It is also important that the container be capable of mass production at an acceptable cost.
A container for industrial chemicals with similar features is disclosed in U.S. Pat. No. 3,156,383. This container is made of plastic and has an opening which is sealed after the container is filled. The outlet is provided in a threaded neck and is closed by an integrally formed, rupturable diaphragm having a pin connected to it which terminates in a flat handle or key. An internally threaded cap has a recess which allows it to be screwed onto the neck without turning the handle. When the container is to be opened, the cap is unscrewed and turned upside down so that a slot in the top of the cap engages the handle and torque may be applied to the handle through the cap to rupture the diaphragm. Since the container can only be opened by tearing the diaphragm, it is immediately evident whether or not the container has been tampered with. The cap may then be used in a conventional manner to reseal the opened container.
In attempting to make containers of polyethylene with a rupturable diaphragm sealing the opening, such as squeezable tubes for dispensing a wide variety of products, it has been found to be difficult to obtain a clean tear. The tendency is for the polyethylene to separate along an unpredictable line leaving an opening with a ragged, rough edge.
It is a primary object of this invention to provide an improved container with an integral sealing member extending across the outlet which must be torn away for access to the contents of the container and therefore provides a visible indication of tampering.
It is another object of the invention to provide such a container made of a thermoplastic material, and preferably polyethylene, in which the sealing member tears cleanly from the outlet.
It is still another object of the invention to provide a container satisfying the previous objects which also has gripping members on a resealing cap which engage gripping members on the sealing member such that the force required to tear the sealing member free from the outlet can be applied with a mechanical advantage provided by the cap.